Week 16 shows South-East Europe shifting into a transit and balancing corridor

Cross-border electricity flows across South-East Europe (SEE) accelerated in Week 16, reinforcing the region’s evolution from separate national markets into an increasingly integrated transit and balancing corridor. For investors and traders, the implication is straightforward: as power increasingly moves through SEE rather than only being produced and consumed within it, price formation and risk are becoming more regional—and more exposed to events elsewhere in Europe.

Imports down as exports surge

Total net imports across SEE declined by 13.11% week-on-week to 886 GWh. The drop was not driven by weaker demand; instead, export activity rose sharply—by more than 65%—while imports increased only marginally. That pattern points to a rebalancing of where electricity is flowing within the region rather than a contraction in overall system activity.

Greece leads a major export-position swing

A key driver was a change in export positions among major SEE markets. Greece shifted from close to balanced trade to a strong net exporting position, swinging from roughly -7 GWh to over -120 GWh—the most pronounced move in the region. Bulgaria and Türkiye also strengthened their export profiles, supported by improved generation availability, particularly from renewables, and favourable price spreads versus neighbouring markets.

Some exporters lose ground; Serbia turns importer

Not all countries benefited from the same direction of flow. Croatia reduced its export volumes significantly, while Serbia moved from a marginal exporter to a net importer. The shift reflected tightening domestic supply conditions and increased reliance on imports to balance its system.

Italy remains the dominant demand sink

Italy continued to function as the primary structural importer in the region. Its already substantial net import position increased by more than 5% week-on-week to approximately 1,056 GWh, reinforcing its role as the main destination for power drawn from surrounding markets.

Renewables variability and price differentials reshape flows

The underlying mechanism behind these shifts is the interaction between generation variability and price differentials. As renewable output rose in parts of SEE—especially wind generation in Greece and Türkiye—excess electricity was pushed into neighbouring systems. At the same time, countries facing renewable shortfalls or hydro declines increased imports, producing a highly dynamic flow environment.

SEE’s growing role as a transit corridor

The scheduled-flow picture described for Week 16 shows dense interconnections with electricity moving across multiple corridors at once. Directional patterns included northbound exports from Greece into the Balkans, east-west exchanges involving Romania, Hungary and Serbia, and sustained inflows into Italy from Central European markets.

Most importantly, SEE is increasingly acting as a transit region rather than only an end-user market: electricity is flowing through the area on its way between larger trading zones. Bulgaria and Serbia stand out in this description as junction points between major trading areas.

More interconnection means faster price transmission—and new risks

This intensification of cross-border flows is changing how prices behave locally. As interconnector usage rises, local prices become more sensitive to conditions in neighbouring markets—for example, shortages in Central Europe can translate quickly into higher prices in SEE when power is redirected toward higher-priced areas. Conversely, surplus generation within parts of SEE can depress prices across the region as exports expand.

Transmission capacity is central to this process: it no longer functions only as a constraint but also as an active driver of market behaviour. Congestion can create price separation, while unconstrained flows support convergence. In Week 16, Central European price alignment suggested that interconnectors were operating efficiently enough for signals to propagate across borders.

That connectivity also introduces additional vulnerability. As systems become more interconnected, local networks are exposed to external shocks; disruptions caused by technical issues, weather events or geopolitical factors can cascade across SEE.

Trading opportunities narrow; balancing needs grow

For trading desks, stronger cross-border integration keeps arbitrage strategies based on price differentials relevant but may reduce how long spreads remain available as markets become more efficient. Meanwhile, greater volatility in flows—linked to renewable variability—raises uncertainty and increases demands on risk management.

The changing flow profile also elevates the importance of balancing markets. With power movements becoming more dynamic, system operators must manage real-time imbalances more actively. This challenge is particularly acute where renewable penetration rises but flexibility resources such as storage and demand response remain limited.

What comes next: investment pressure alongside resilience concerns

Looking ahead, SEE’s role as both a transit and balancing hub is expected to grow further as investments expand interconnection capacity—including new high-voltage corridors linking the Balkans with Central Europe and Italy. The stated goal of such build-out is deeper integration into the European energy market through reduced isolation and improved liquidity.

At the same time, greater dependence on cross-border flows raises questions about resilience during scarcity periods when countries rely more heavily on imports. Ensuring interconnector reliability becomes critical, implying continued investment in grid infrastructure alongside coordinated planning among transmission system operators.

Week 16 therefore marks another step in SEE’s structural evolution: cross-border flows are no longer peripheral features but central drivers of regional market dynamics—shaping prices, influencing generation decisions, and determining how supply meets demand across multiple national systems.